Low sintering temperature for lead‐free BiFeO ₃ ‐BaTiO ₃ ceramics with high piezoelectric performance

Abstract

Abstract Through modification of the heat‐treatment process using a higher heating rate and a lower binder burnout temperature, the piezoelectric performance of water‐quenched 0.67Bi 1.05 FeO 3 ‐0.33BaTiO 3 (BF33BT) lead‐free piezoelectric ceramics was improved. The observed physical properties of BF33BT ceramics were very sensitive to the process temperatures. The sintering temperature ( T S ) was changed within a narrow temperature range, and its effects were investigated. The largest rhombohedral distortion (90°‐ α R = 0.14°) and tetragonality ( c T / a T = 1.022) were observed for the ceramic sintered at 980°C, and its Curie temperature was 476°C. This ceramic showed good piezoelectric properties and large grains; the piezoelectric sensor charge coefficient ( d 33 ) was 352 pC/N, and the piezoelectric actuator charge coefficient ( ) was 270 pm/V. The high piezoelectric performance and low T S of BF33BT ceramics indicate their potential as new low‐cost eco‐friendly lead‐free piezoceramics.